State detecting system and device employing the same

ABSTRACT

A state detecting system which can detect state of power storage at high precision even with lesser characteristic data to be used for calculation, and a device employing the same. The state detecting system has a memory for storing a characteristic data, calculation information, and set information, an arithmetic unit for calculating state information indicative of state of said power storage and calculating correction information for performing correction, a first correcting unit for correcting input of said arithmetic means, and a second correcting unit for correcting information stored or set in the storage.

CROSS REFERENCE

This application is a continuation of U.S. application Ser. No.11/033,057 filed on Jan. 10, 2005, now U.S. Pat. No. 7,085,661, issuedAug. 1, 2006, which was a continuation of U.S. application Ser. No.10/387,524 filed on Mar. 14, 2003, now abandoned.

BACKGROUND OF THE INVENTION

The present invention relates to a novel state detecting device fordetecting states such as charge condition, residual capacity in a powerstorage means such as a lithium secondary battery, a nickel hydridebattery, a lead seal battery, an electric double layer capacitor, and toa power source unit, a distribution type power storage device, and anelectric vehicle which use the state detecting device.

In a power source unit, a distribution type power storage device and anelectric vehicle employing power storage means, such as a battery, astate detecting device is employed for detecting state of the powerstorage means in order to safely and effectively use the power storagemeans. The state of the power storage means represents state of charge(hereinafter abbreviated as “SOC” indicative how much charged or howmuch dischargeable charge amount resides, residual capacity, or state ofhealth (hereinafter abbreviated as “SOH”) indicative of how muchexhausted or weakened or degree of deterioration.

The SOC in the power source unit of a portable equipment, an electricvehicle and so forth can be detected by integrating a discharge currentfrom a fully charged state and calculating a ratio of a charge amountresiding in the power storage means (hereinafter referred to as“residual capacity”) versus a maximum chargeable charge amount(hereinafter referred to as “full capacity). However, many power storagemeans varies the full capacities depending upon SOH, temperature and soforth, it is difficult to accurately detect SOC with respect to secularchange and variation of environment.

In order to solve such problem, as conventional residual capacitypredicting method in consideration of deterioration of battery, therehas been known one disclosed in Japanese Patent Application Laid-OpenNo. Heisei 10-289734. FIG. 10 is an illustration showing a residualcapacity predicting method of the above-identified publication. In thismethod, an initial battery characteristics is corrected by a temperaturecorrection coefficient derived on the basis of a temperature of thebattery and a deterioration correction coefficient derived based ondeterioration of the battery, and a residual capacity of the battery isderived on the basis of the corrected battery characteristics, adischarge current during discharging and a terminal voltage.

In Japanese Patent Application Laid-Open No. Heisei 11-218567, there isshown a method for deriving a battery characteristics upon occurrence ofdeterioration by correcting an initial battery characteristics inrelation to a temperature correction coefficient, an internal resistordeterioration correction coefficient, a capacitor deteriorationcorrection coefficient.

In Japanese Patent Application Laid-Open No. 2000-166105, there has beendisclosed a control unit detecting a charge condition on the basis ofcharge and discharge current, detecting a power storage condition on thebasis of a voltage and controlling a charge condition on the basis ofsuch detections.

In Japanese Patent Application Laid-Open No. 2000-166109, there has beendisclosed a charge condition detecting device deriving an electromotiveforce based on a charge and discharge current and voltage and having acalculating means for deriving a charge characteristics on the basis ofthe electromotive force and the charge characteristics.

In Japanese Patent Application Laid-Open No. 2001-85071, there isdisclosed a temperature detecting device predicting respectivetemperatures of a set battery modules on the basis of voltages betweenterminals and currents flowing therethrough.

In the residual capacity predicting method disclosed in the foregoingJapanese Patent Application Laid-Open No. Heisei 10-289734, inconsideration of influence for temperature or deterioration, theseinfluences are taken in as temperature correction coefficient ordeterioration correction coefficient for correcting parameters necessaryfor calculation of the residual capacity with these correctioncoefficients derived through complicate derivation processes. Therefore,it is concerned whether the value per se of the correction coefficientis correct or whether all battery characteristics are corrected.

In addition, the power storage means of some kind also hascharacteristics, such as charge efficiency, memory effect and so forth,and is required to make correction in consideration of thesecharacteristics in precision of residual capacity with high precision.On the other hand, the initial characteristics of the power storage meangenerally contain individual difference. Correction for individualdifference is also necessary in prediction of residual capacity withhigh precision.

Namely, in order to perform state detection, such as prediction ofresidual capacity with high precision, it becomes necessary effectaccurate modeling of the characteristics to take in a plurality ofparameters. Furthermore, it is required to perform correction associatedwith secular change or environmental variation of these parameters.

Therefore, significant time and attention have to be paid for obtainingthe initial characteristics and a plurality of parameters of the powerstorage means. However, no matter how complicate it is, the result ofarithmetic operation is nothing but prediction on the basis of thetheory or model of the battery characteristics. Therefore, it is stilledconcerned whether the result of prediction is correct with respect to atrue value.

Therefore, it has been found that, in order to realize state detectionof the power storage means at high precision and simply in calculationwith characteristic data to be used in arithmetic operation, correctionby comparing the result of state detection with the true value or logicand feeding back to subsequent arithmetic operation with learning thedifference, is required, and break through thereof is necessary. Sinceit is not possible to directly measure the state of the battery, such asSOC or SCH, an important problem is how to derive the true value orlogic.

On the other hand, in Japanese Patent Application Laid-Open No. Heisei11-218567, Japanese Patent Application Laid-Open No. 2000-166105,Japanese Patent Application Laid-Open No. 20000-166109 and JapanesePatent Application Laid-Open No. 2001-85071, it is failed to disclose toperform correction feeding back a correction information obtainedthrough arithmetic operation to subsequent arithmetic operation, and tocorrect storage information necessary for the arithmetic operation, andto perform state detection of the power storage means on the basis of aplurality of particular arithmetic operation and a plurality of varyinginformation.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a state detectionsystem to perform correction for feeding back correction informationobtained through the predetermined arithmetic operation to subsequentarithmetic operation and storage information to make a characteristicdata to be used in arithmetic operation at least being accurate toenable detection of state, such as state of charge, state of health orthe like, and a power source unit, a power storage device and anelectric vehicle.

The present invention is directed to a state detecting system comprisinga storage means for storing a characteristic data with respect to apower storage means arithmetically obtained on the basis of the measuredinformation obtained by measuring a measuring object with respect to thepower storage means by measuring means, calculation information relatingto the arithmetic operation of the data, and set informationpreliminarily set relating to the characteristic data and thecalculation information, an arithmetic means for calculating stateinformation indicative of state of the power storage means on the basisof the measured information and set information and calculatingcorrection information for performing correction by comparing acalculation result calculated and the set information, a firstcorrecting means for correcting input of the arithmetic means on thebasis of correction information obtained by the arithmetic means, or asecond correcting means for correcting information stored or set instorage means based on correction information obtained by the arithmeticmeans, and a communication means for communicating a calculation resultobtained from the arithmetic means to other device.

More particularly, the state detecting system according to the presentinvention comprises a measuring means for measuring one or more ofvoltage, current, temperature, resistance and electrolyte concentrationof a power storage means, a storage means for storing at least one ofcharacteristic data of the power storage means, calculation coefficientand calculation procedure and preliminarily set value to be consideredas true value or set information to be a logic considered as truephenomenon, an arithmetic means for calculating state of the powerstorage means on the basis of the measured value of the measuring meansand the set information of the storage means and calculating acorrection amount by comparing the calculation result and the setinformation, and communication means for communicating the calculationresult of the arithmetic means to other device, and a correcting meansfor correcting the value of the storage means or input of the arithmeticmeans. By this, it can perform correction by comparing the calculationresult and set information and feeding back the difference to subsequentcalculation with learning. Therefore, it can be realized the statedetection system which can detect state of power storage means achievinghigh accuracy with requiring lesser characteristic data to be usedsimply in calculation.

The correction means according to the present invention may determine acorrection amount based on discrepancy of the calculation result of thecalculation means and set information. For example, it is naturalcondition that charge state increases during charging. If discrepancy inthat the charge state decreases during charging, this is corrected. Inaddition, it is natural when charge and discharge is performed withinthe allowable charge an discharge current value capable of charging anddischarging the power storage within allowable use voltage range,overcharging or over discharging is not detected. If overcharging orover discharging is detected, allowable charge and discharge current iscorrected. As set forth, according to the present invention, normalcharacteristics or natural phenomenon is taken as set information andcompares with the calculation result to correct the value of the storagemeans or input of the arithmetic means is corrected with learning.

On the other hand, in the present invention, the value of the measuringmeans, calculation result or calculation procedure of the arithmeticmeans, when the current value is smaller than or equal to thepredetermined value may be determined as the correction value. Forexample, under a condition where influence of self-discharge is smalland if current value is 0A, charge state varies little. Namely, whencurrent value is 0A, variation amount of charge state being 0 is takenas set value as true value. If current value is 0A, charge state isvaried; correction is performed to feedback the variation amount to thesubsequent calculation with learning.

The storage means of the present invention has two or more mutuallydifferent calculation procedures. The arithmetic means can derive thecorrection value from the calculation results of the calculationprocedures to perform correction for feeding back the correction valueto the subsequent calculation with learning.

On the other hand, the arithmetic means has the charge state calculatingmeans and current integration means of the power storage means tocalculate capacity of the power storage means based on different twocharge state and current integration value die the period. In this case,the storage means stores the initial capacity of the power storagemeans, and correction means may determine the correction informationbased on the capacity and initial capacity of the power storage means.

The present invention is characterized by a power source unit comprisingpower storage means, measuring means for measuring at least one ofvoltage, current, temperature, electric resistance and electrolyteconcentration, and a state detecting system deriving state informationof the power storage means on the basis of measured information measuredby the measuring means, the state detecting system comprising statedetecting system set forth above.

On the other hand, the present invention is characterized by a powerstorage device comprising a commercial power source connected to aswitch, a photovoltaic generation device connected to the commercialpower source via the switch, a load device connected to the photovoltaicgeneration device via a switch, a control converter controlling power ofthe commercial power source and the photovoltaic generation device andconnected to the switch of the commercial power source via a switch, acontrol unit commanding switching of the switch of the commercial powersource and the switch of the control converter and commanding the power,power storage means, measuring means for measuring at least one ofvoltage, current, temperature, electric resistance and electrolyteconcentration, and a state detecting system deriving state informationof the power storage means on the basis of measured information measuredby the measuring means, the state detecting system comprising statedetecting system set forth above.

The present invention is characterized by an electric vehicle comprisinga generator performing power generation by revolution and rotation of amotor for driving wheel and the wheel or motor generator driving wheeland performing power generation by rotation of the wheel, a controlconverter connected to the motor and generator or the motor generatorand converting a power thereof, a control unit designating the power ofthe control converter, power storage means connected to the controlconverter, a measuring means for measuring at least one of voltage,current, temperature, electric resistance and electrolyte concentration,and a state detecting system deriving state information of the powerstorage means on the basis of measured information measured by themeasuring means, the state detecting system comprising state detectingsystem set forth above, and the control unit being controlled by acommunication means.

The present invention is characterized by a hybrid vehicle comprising aninternal combustion engine, a generator performing power generation byrevolution of motor assisting driving force of wheel connected to theengine and rotation of wheel and a motor generator connected to theengine and assisting driving force of the engine and performing powergeneration, a control converter connected to the motor and the generatoror the motor generator, for converting a power thereof, a control unitdesignating the power of the control converter, a power storage meansconnected to the control converter, a measuring means for measuring atleast one of voltage, current, temperature, electric resistance andelectrolyte concentration, and a state detecting system deriving stateinformation of the power storage means on the basis of measuredinformation measured by the measuring means, the state detecting systemcomprising state detecting system set forth above, and the control unitbeing controlled by a communication means.

It is preferred that the power storage means is selected among lithiumsecondary battery, a nickel hydride battery, a lead seal battery, anelectric double layer capacitor and so forth.

As set forth above, by the present invention, since correction isperformed by comparing the calculation result with the set information,such as set value or logic of the calculation result to feedback to thesubsequent calculation with learning. Therefore, state detecting systemdetecting state information of the power storage means with highprecision with smaller characteristic data to be used for calculationwith using simple arithmetic expression for calculation, the powersource unit, distributed type power storage device, the automotivevehicle, can be realized.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood more fully from the detaileddescription given hereinafter and from the accompanying drawings of thepreferred embodiment of the present invention, which, however, shouldnot be taken to be limitative to the invention, but are for explanationand understanding only.

FIG. 1 is a constructional illustration of a power source unit accordingto the present invention;

FIG. 2 is a block diagram sowing a calculation process of the powersource unit according to the present invention;

FIG. 3 is a circuit diagram showing an equivalent circuit of a powerstorage means according to the present invention;

FIG. 4 is a diagrammatic illustration showing a relationship between SOCand allowable charge and discharge current of power storage meansaccording to the present invention;

FIG. 5 is a diagrammatic illustration showing a voltage variation uponcharging by a pulse current of the power storage means according to thepresent invention;

FIG. 6 is a constructional illustration of the power source unitaccording to the present invention;

FIG. 7 is a diagrammatic illustration showing a relationship of OCV andSOC of the power storage means according to the present invention;

FIG. 8 is a constructional illustration of a distributed type powerstorage device of sunlight applied the state detection system and thepower source unit according to the present invention;

FIG. 9 is a constructional illustration of an automotive vehicle appliedthe state detection system and the power source unit according to thepresent invention; and

FIG. 10 is a constructional illustration showing the conventionalresidual capacity predicting method.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be discussed hereinafter in detail in termsof the preferred embodiment of the present invention with reference tothe accompanying drawings. In the following description, numerousspecific details are set forth in order to provide a thoroughunderstanding of the present invention. It will be obvious, however, tothose skilled in the art that the present invention may be practicedwithout these specific details. In other instance, well-known structuresare not shown in detail in order to avoid unnecessary obscurity of thepresent invention.

First Embodiment

FIG. 1 is a constructional illustration of a power source unit accordingto the present invention. In FIG. 1, the reference numeral 101 denotespower storage means, 102 denotes measuring means, 103 denotes storagemeans, 104 denotes arithmetic means, 105 denotes communication means,106 denotes first correction means and 107 denotes second correctionmeans. The power storage means 101 is formed with a device having apower storage function, such as a lithium secondary battery, a nickelhydride battery, a lead seal battery, an electric double layer capacitorand so forth.

The measuring means 102 is formed with a sensor or an electric circuitmeasuring voltage, current, temperature, resistance, battery electrolyteconcentration and so forth, to obtain necessary measured information.

The storage means 103 is constructed with a memory device, such as anEEPROM, flash memory, a magnetic disk and so forth to store calculationinformation including at least one of characteristic data, calculationcoefficient and calculation procedure, and set value to be considered asa preliminarily set true value relating to the calculation informationor set information consisted of logic considered as true phenomenon.

The arithmetic means 104 is formed with a microprocessor, a computer orthe like, and derives a state information of the power storage means 101on the basis of a measuring value of the measurement means 102 and avalue of the storage means 103. On the other hand, the result ofcalculation and the set information are compared to calculate thecorrection information to be these correction amounts. As state of thepower storage means 101, there are various abnormality, such as SOC,SOH, allowable current, continuous charge and discharge period,allowable temperature, overcharging, over discharging and so forth.

The communication means 105 is constructed with a device or circuit forcommunicating a serial number, such as CAN, Bluetooth and so forth or adevice or circuit communicating an ON-OFF signal, such as photo-coupler,relay and so forth. Then, a result of calculation calculated by thearithmetic means 104 is transmitted to other controller, display elementor the like (not shown).

The first correction means 106 is constructed with a cache memory, abuffer memory, such as SRAM or the like, a register. Correction isperformed by varying a value of the measuring means 102, a value of thestorage means 103, a result of calculation of the arithmetic means 104on the basis of a correction value derived by the arithmetic means 104.

The second correction means 107 is constructed with a writing circuit ofEEPROM, flash memory and so forth as the storage means 103 or a writingcircuit of the magnetic disk or the like and re-writes the value in thestorage means 103 based on the correction value calculated by thearithmetic means 104.

While the first correction means 106 and the second correction means 107are employed in the shown embodiment, it is possible to use one of thesecorrection means or to employ other construction. On the other hand, byemploying a microcomputer, in which an A/D converter, a flash memory, amicroprocessor, a communication circuit are integrated on the samedevice, the measuring means 102, the storage means 103, the arithmeticmeans 104, the communication means, the first correction means 106 andthe second correction means 107 can be integrated on the same device. Onthe other hand, these can be used in common with other control unit.

With the shown embodiment, the result of calculation per se is comparedwith the set value or the set information set as logic to performcorrection with feeding back to subsequent arithmetic operation withlearning the difference between the result of calculation and the setvalue or the set information. Therefore, it becomes possible to realizethe state detection method and state detection system of the powerstorage means which is high accuracy with lesser characteristic data tobe used in arithmetic operation and simple in arithmetic operation, anda power source unit employing the same.

Second Embodiment

FIG. 2 is a block diagram showing a state detection method of the powerstorage means according to the present invention. In FIG. 2, in a stepof measuring and reading, voltage, current, temperature, resistance,electrolyte concentration and so forth of the power storage means 101 ismeasured to read the measuring value of the first correction means 106or the arithmetic means 104 or a value of the storage means 103. Incalculation, state of the power storage means 101 is calculated on thebasis of the read value. In discrepancy judgment, the result ofcalculation and the set value or logic is compared to make judgment ofdiscrepancy. If no discrepancy is found, process does end to repeat thesame sequence. If discrepancy is found, related parameters are correctedat a step of correction and writing to terminate writing in the memory.By repeating this sequence, correction to feedback the discrepancy tosubsequent arithmetic operation with learning can be performed.

Here, discrepancy between the result of calculation and the set value orlogic means that, for example, it is natural logic to increase chargestate during charging, discrepancy is found when the charge state isdecreased during charging. Also, it is similarly the logic that thecharge state is decreased during discharging, or charge state is notvaried under the condition where influence of self-discharge can beignored during resting. If discrepancy is case to this, correction iseffected. Then, matrixing of such items may be performed to makediscrepancy judgment with taking the matrix as discrepancy matrix.

While it is not possible to directly measure the state of the powerstorage means, the foregoing obvious phenomenon or characteristics aretaken as set information to compare with the result of calculation. Ifdiscrepancy is found, the value of the storage means and the input ofthe arithmetic means are corrected with learning.

By this, it becomes possible to realize the state detection system ofthe power storage means which is high accuracy with lessercharacteristic data to be used in arithmetic operation and simple inarithmetic operation, and a power source unit employing the same.

FIG. 3 is a circuit diagram showing an equivalent circuit of the powerstorage means. In FIG. 3, the reference numeral 201 denotes anelectromotive force (OCV), 302 denotes an internal resistor (R), 303denotes an impedance (Z), 304 denotes a capacitor component (C). Thereare illustrated a parallel connection pair of the impedance 303 and thecapacitor component 304 and a series connection of the internal resistor302 and the electromotive force 301. When a current I is applied to thepower storage means, a voltage (CCV) between the terminals of the powerstorage means is expressed by an equation (1).CCV=OCV+1R+Vp  (1)

wherein Vp is polarized voltage, Z and C are voltages of the parallelconnection pair.

OCV is used for calculation of SOC or allowable charge and dischargecurrent. In the condition where the power storage means is charged anddischarged, it is not possible to directly measure OCV. Therefore, OCVis derived by subtracting IR drop and Vp from CCV as expressed by thefollowing equation (2).OCV=CCV−IR−Vp  (2)

FIG. 4 is a diagrammatic illustration showing SOC, an allowable chargecurrent and allowable discharge current of the power storage means.Associating with increase of SOC, the allowable discharge current isincreased and allowable charge current is decreased. Assuming themaximum allowable voltage of the power storage means is Vmax and minimumallowable voltage is Vmin, the allowable charge current Icmax andallowable discharge current Idmax are respectively expressed by thefollowing equations (3) and (4).Icmax=(Vmax−OCV)/Rz  (3)Idmax=(OCV−Vmin)/Rz  (4)

wherein Rz is equivalent impedance of R, Z, C in FIG. 3.

Accordingly, upon discrepancy is found in that overcharging or overdischarging is detected upon charging and discharging at a currentsmaller than or equal to Icmax and Idmax, the value of Rz is corrected.For example, Rz is increased by 1%.

FIG. 5 is a diagrammatic illustration showing variation of voltageduring charging by a pulse current of the power storage means. A curveof CCV shown by a solid line is risen from a charge start timing (A) andis abruptly drops at a charge terminating timing (B). Dropping is due toIR drop. Subsequently, CCV is decreased moderately to gradually approachto the set information of OCV shown by one-dotted line. A voltagevariation in this period mainly corresponds to Vp. On the other hand,the set information of OCV not influenced by the IR drop or Vp isincreased from A to B during charging but is not varied during a periodbetween B where a current is 0A to D (under the condition whereinfluence of self-discharge or environmental temperature can beignored). In contrast to this, the calculated value of OCV shown bybroken line is not consistent with the set information of OCV, and showsmoderately decreasing curve even from B to D.

When the equation (2) is used in calculation of OCV, R can be directlyobtained by actually measuring CCV and I and expressed by the followingequation (5) using variation amount dCCV and dI in a short period.R=dCCV/dI  (5)

Therefore, with the present invention, taking the fact that variation ofOCV is 0V at 0A as set value, for example, when the calculated value ofOCV during this period is varied as shown in FIG. 5, Vp is corrected.

On the other hand, when SOC is derived from OCV, the set value or logicof SOC and the calculated value are also varied as shown in FIG. 5. Evenin this case, it becomes possible to detect discrepancy of Vp. Then,after correction of Vp, it is fed back to subsequent calculation.

Third Embodiment

The table 1 is a table showing a relationship between variation of SOCof the present invention and correction amount of Vp. With taking a timescale as t, and taking a timing where the current value becomes 0A ast=0, the correction amount of Vp is determined from variation of SOC att<0 and variation of SOC at t>0. For example, if variation of SOC at t<0is increase and variation of SOC at t>0 is also increase, Vp isdecreased by 1%.

TABLE 1 SOC Variation SOC Variation (t < 0) (t > 0, Current 0 A) VpCorrection Increase Increase −1% Increase Decrease +1% Decrease Increase+1% Decrease Decrease −1%

Then, these calculation is repeated for a plurality of times as timeelapsed. By this, Vp gradually approaches to the set value by learningeffect. Namely, Vp is automatically tuned.

While the absolute value of the correction amount is uniform at 1% here,it is preferred that this value is optimized depending upon kind of thepower storage means, current pattern of the load, measurement error ofthe measuring means and so forth. On the other hand, as shown, it ispreferred to apply Fuzzy theory for indicating direction of correction.

While state of the power storage means cannot be measured directlysimilarly to SOC or OCV, according to the present invention, thecharacteristics or normal phenomenon in the period where the currentvalue is less than or equal to a predetermined value set forth above asset value or logic, the correction amount is derived by Fuzzy theory bycomparing the result of calculation per se. This is fed back to thesubsequent calculation to repeat learning calculation.

Therefore, whenever calculation is repeated, precision can be improved.On the other hand, since the individual difference of the initialcharacteristics, environment dependency, secular change and so forth areautomatically tuned. Thus, these plurality of parameters and data ofcorrection coefficient can be eliminated.

For example, in the foregoing example, Vp depends on complicateparameter, such as individual difference or secular change, and furtherindividual difference of secular change and so forth. Upon modeling andreproducing these parameters accurately for taking in calculation, itbecomes necessary to obtain the initial characteristics, a plurality ofparameters, data to require substantial period and load. However, in thepresent invention, influence of these individual difference, secularchange and so forth are calculated with learning under actual useenvironment, these parameters are not required.

Fourth Embodiment

FIG. 6 is a constructional illustration of the power source unitaccording to the present invention. In FIG. 6, the reference numeral 701denotes a calculation procedure A, 702 denotes a calculation procedureB, 703 denotes a correction amount calculation procedure. The arithmeticmeans 104 shows a part of the calculation procedure, and the arithmeticmeans have the arithmetic procedure A and the arithmetic procedure B.

For example, the calculation procedure A 701 is taken as arithmeticprocedure of SOC (hereinafter referred to as SOCV) derived from OCV setforth above, and the calculation procedure B 702 is taken as calculationprocedure of SOC (hereinafter referred to as SOCi based on a currentintegration. In calculation of SOCi, the equation (6) is used.SOCi=SOCo+100×d∫I/Q  (6)

wherein SOCo is an initial value of SOC upon starting of charging anddischarging, d∫I is a various amount of the current integrated value, Qis a maximum chargeable charge amount (full capacity). Assuming a chargeefficiency of the power storage means as η, an integrated charge currentas ∫Ic and an integrated discharge current as ∫Id, d∫I is expressed bythe following equation (7)d∫I=η×∫Ic−∫Id  (7)

SOCi is superior in indicating variation amount in a short period,namely response characteristics, for directly calculation the current.However, an absolute value is not always correct due to individualdifference or secular change of Q, influence of η or erroneousaccumulation of current integrator.

On the other hand, SOCV can be calculated the absolute value with highprecision by learning. However, it takes a little period in learning,response characteristics is relatively low in comparison with SOCi.Therefore, by the correction amount calculation procedure 703, variationof SOCV and SOCi in relatively long period is compared to derive thecorrection amount to correct the item of d∫I/Q of the equation (6). Onthe other hand, SOCo is corrected with SOCV at arbitrary timing.

By this, it becomes possible to achieve both of response characteristicsof SOCi and high precision calculation of SOCV. On the other hand, thecorrection amount is derived by comparing the results of calculation perse to feed back the results of calculation for subsequent calculation torepeat learning calculation. Since precision can be improved.Furthermore, since the individual difference of Q, secular change,influence of η and accumulation of error in the current integrator canbe corrected by learning calculation based on SOCV, these correctionparameters are not required. Accordingly, it becomes possible toeliminate significant period and load spent for obtaining theseparameters or data.

In addition, as the calculation procedure A 701, similar effect can beobtained using SOC calculated from the resistance of the power storagemeans or SOC calculated from electrolyte concentration.

FIG. 7 is a diagrammatic illustration showing a relationship between OCVand SOC of the power storage means. Associating with increase of SOC,OCV is increased gradually. Such relationship of SOC and OCV is shown inmany of power storage means, such as lithium secondary battery, electricdouble layer capacitor and so forth.

Fifth Embodiment

In the shown embodiment, using the characteristics of the power storagemeans of FIG. 7, the maximum chargreable charge amount (full capacity) Qcan be derived. For example, assuming that two different charge statesare SOC1 and SOC2, residual capacity corresponding to these are Q1 andQ2 and current integrated value there between is dQ (=d∫I), thefollowing equations (8) to (11) are established:

$\begin{matrix}{{{SOC}\; 1} = {100 \times Q\;{1/Q}}} & (8) \\{{{SOC}\; 2} = {100 \times Q\;{2/Q}}} & (9) \\\begin{matrix}{{{{SOC}\; 1} - {{SOC}\; 2}} = {100 \times {\left( {{Q\; 1} - {Q\; 2}} \right)/Q}}} \\{= {100 \times {{dQ}/Q}}}\end{matrix} & (10) \\{Q = {100 \times {{dQ}/\left( {{{SOC}\; 1} - {{SOC}\; 2}} \right)}}} & (11)\end{matrix}$

Thus, full capacity Q of the power storage means can be derived.Similarly, full capacity Q can be derived using SOC derived from theelectrolyte concentration or internal resistor and the currentintegration value.

Then, by feeding back Q thus derived to the equation (6), influences ofindividual difference of Q and secular change can be corrected to permitfurther precise state detection. On the other hand, correction parameterof the individual difference and secular change becomes unnecessary toeliminate significant time and load required for obtaining parametersand data.

Sixth Embodiment

Table 2 is a table showing a relationship of the correction coefficientK of the full capacity Q relative to the initial capacity Q0 of thepower storage means. In this embodiment, a ratio between the initialcapacity of the power storage means stored in the storage means and thefull capacity Q derived from the equation (11) is derived to obtain acorrection coefficient K depending thereon.

TABLE 2 Q/Qo 1.0 0.9 0.8 0.7 0.6 0.5 K 1.0 0.81 0.64 0.49 0.36 0.25

In general, the power storage means decreases the full capacityassociating with secular change. At the same time, the internalresistance is increased. A continuous charge and discharge periodderived from the residual capacity, allowable charge current andallowable discharge current derived from equations (3) and (4) andallowable heat generation amount (or cooling control) or allowablecharge and discharge power and so forth have to be corrected the initialvalues depending upon secular change. The foregoing correct coefficientis used for correction of these. Then, these values are preferablyoptimized depending upon the kind or system of the power storage means.

As set forth above, with the present invention, influences of individualdifference or secular change of the continuous charge and dischargeperiod, allowable charge current and allowable discharge current andallowable heat generation amount (or cooling control) or allowablecharge and discharge power and so forth is corrected to permit moreprecise state detection. On the other hand, these correction parametersbecomes unnecessary. Accordingly, it becomes possible to eliminatesignificant period and load spent for obtaining these parameters ordata.

Seventh Embodiment

FIG. 8 is a constructional illustration of a photovoltaic generationequipment, to which the state detection system and the power source unitaccording to the present invention is applied. In FIG. 8, the referencenumeral 1001 denotes a commercial power source, 1002 denotes aphotovoltaic generation equipment, 1003 denotes a load device, 1004denotes a control converter, 1005 denotes as a switch, 1006 denotes astate detecting device and 1007 denotes a power source unit.

The state detecting device 1006 is constructed with the measuring means102, the storage means 103, the arithmetic means 104, the communicationmeans 105, the first correction means 106 and the second correctionmeans 107. On the other hand, the power source unit 1007 is constructedwith a series connected circuit in which a plurality of power storagemeans 101 connected in series, and the state detecting device 1006.

Both ends of the series connected circuit of the power storage means 101is connected to the control converter 1004. The control converter 1004is further connected to the commercial power source 1001, thephotovoltaic generation equipment 1002 and the load device 1003 via theswitches 1005 respectively. On the other hand, by a control of a maincontrol unit (MCU) of the control converter 1004, the commercial powersource 1001, the photovoltaic generation equipment 1002 m the loaddevice 1003 are switched by the switches 1005. Also, a command from thestate detection device 1005 is connected by bidirectional communicationbetween the communication means 105 and the MCU.

The photovoltaic generation equipment is an equipments to convert a sunlight into a direct current by solar cells and to output an alternatingcurrent power by an inverter device. On the other hand, the load device1003 is a household electric equipment, such as an air conditioner, arefrigerator, an electronic oven, lighting and so forth, an electricequipment, such as a motor, an elevator, a computer, a medical equipmentand so forth, or a secondary power source unit. Then, the controlconverter 1004 is a charge and discharge device which converts thealternating current power into the direct current power or converts thedirect current power into the alternating current power, and also servesas a controller for controlling charge and discharge and controlling theequipments, such as the photovoltaic generation equipment 1002, the loaddevice 1003 and so forth.

Here, these equipment may incorporate the switch 1005 therein. On theother hand, the power source unit according to the present invention mattake connection other than those illustrated herein. With the shownembodiments, when a sufficient power required by the load device 1003cannot be supplied from the commercial power source 1001 or thephotovoltaic generation equipment 1002, the power is supplied from thepower storage means 101 via the control converter 1004. On the otherhand, when power supply from the commercial power source 1001 or thephotovoltaic generation equipment 1002 becomes excessive, the excessivepower is stored in the power storage means 101 via the control converter1004.

During these operation, the state detecting device 1007 may detect stateof the power storage means 101 by each of the first to the sixthembodiments or the combination thereof. For combination of these,syllogism is applied. On the other hand, the result of state detectionis fed to the control converter 1004 as a control amount for state orallowable charge and discharge current and so forth of the power storagemeans 101. The control converter 1004 controls charging and dischargingdepending thereon. Particularly, since the state detection device 1007can perform high precision state detection, the power storage means 101can be used safely and effectively.

On the other hand, in the embodiment shown, it becomes possible to lowercontract demand or power consumption of the commercial power source 1001and to lower rated power to be generated by the photovoltaic generationequipment 1002 to permit reduction of investment or running cost. Whenpower consumption is concentrated to a certain time zone, the power issupplied to the commercial power source 1001 from the power source unit,and during a time zone where power consumption is small, power isaccumulated in the power source unit to absorb concentration of powerconsumption and to equalize power consumption.

Furthermore, the control converter 1004 monitors power consumption ofthe load device 1003 and controls the load device 1003. Therefore, powersaving and effective use of the power can be achieved. As set forthabove, with the shown embodiment, the state detection method, the statedetection system of the power storage means in high precision and withsmaller number of characteristic data to be used for calculation, andthe power source unit, distribution type power storage device employingthe same can be realized.

Eighth Embodiment

FIG. 9 is a constructional illustration showing an embodiment of anelectric vehicle, to which the state detection system and the powersource unit according to the present invention is applied. In FIG. 9,the reference numeral 1101 denotes a motor generator, 1102 denotes adirect current load device. The motor generator 1101 is connected to theseries connected circuit of a plurality of power storage means 101 viathe control converter 1004. The motor generator 1101 is directly coupledwith a wheel in case of the electric vehicle. In case of a hybridelectric vehicle, an internal combustion engine is further coupled forassisting start-up or driving force (power running) and generation(re-generation). During power running, power is supplied from the powersource unit 1007 to the motor generator 1101. During re-generation,power is supplied from the power generator 1101 to the power source unit1007.

On the other hand, the direct current load device 1102 is an electricload, such as electromagnetic vale, audio unit and so forth, or thesecondary power source unit. The direct current load device 1102 isconnected to the series connected circuit of the power storage means viathe switch 1005.

Even in the shown embodiment, the state detection device 1007 may employrespective of the first to sixth embodiment or combination thereof. Viathe communication means, state of the power storage means 101 or controlamount of the allowable charge and discharge current or the like is fedto the control converter 1004 so that the control converter 1004 maycontrol charging and discharging depending thereon. Particularly, sincethe state detection device 1007 may perform state detection with highprecision, the power storage means 101 may be used safely andeffectively.

By this, the hybrid electric vehicle which can assist to a torque of theinternal combustion engine upon star-running and can accumulate kineticenergy by converting into electric power, can be realized.

With the present invention, by performing correction with feeding backthe correction information obtained by predetermined arithmeticoperation for the subsequent calculation and storage information forcalculation, it becomes possible to provide the state detection systemwhich can detect state, such as state of charge or state of health ofthe power storage means with high precision even when amount ofcharacteristic data to be used for calculation is small, the powersource unit, power storage device and electric vehicle employing thesame.

1. A system for detecting a state of an electric storage devicecomprising: a memory, wherein said memory stores storage informationincluding characteristic data of said storage device, calculation datarequired for detecting said state, and set data based on a property ofsaid storage device or a phenomenon caused therein; a calculator,wherein said calculator determines state information based on inputinformation including measurement data from a measurement instrument andsaid storage information, and wherein said calculator providescorrection data corresponding to said input information when said stateinformation differs from said set data; and a correction unit, whereinsaid correction unit changes said input information based on saidcorrection data; wherein said input information includes internalresistance information of said storage device, and wherein saidcorrection data includes internal resistance correction datacorresponding to said internal resistance information, and wherein saidcorrection unit rewrites said internal resistance information in saidmemory on the basis of said internal resistance correction data.
 2. Asystem for detecting a state of an electric storage device comprising: amemory, wherein said memory stores storage information includingcharacteristic data of said storage device, calculation data requiredfor detecting said state, and set data based on a property of saidstorage device or a phenomenon caused therein; a calculator, whereinsaid calculator determines state information based on input informationincluding measurement data from a measurement instrument and saidstorage information, and wherein said calculator provides correctiondata corresponding to said input information when said state informationdiffers from said set data; and a correction unit, wherein saidcorrection unit changes said input information based on said correctiondata; wherein said input information includes internal resistanceinformation of said storage device, and wherein said correction dataincludes internal resistance correction data corresponding to saidinternal resistance information, and wherein said input informationfurther includes polarized voltage information of said storage device,and wherein said correction data includes said polarized voltagecorrection data corresponding to said polarized voltage information. 3.A system for detecting a state of an electric storage device comprising:a memory, wherein said memory stores storage information includingcharacteristic data of said storage device, calculation data requiredfor detecting said state, and set data based on a property of saidstorage device or a phenomenon caused therein; a calculator, whereinsaid calculator determines state information based on input informationincluding measurement data from a measurement instrument and saidstorage information, and wherein said calculator provides correctiondata corresponding to said input information when said state informationdiffers from said set data; and a correction unit, wherein saidcorrection unit changes said input information based on said correctiondata; wherein said input information includes internal resistanceinformation of said storage device, and wherein said correction dataincludes internal resistance correction data corresponding to saidinternal resistance information, and wherein said input informationfurther includes capacity information of said storage device, whereinsaid calculator provides said correction data as a result of at leasttwo different calculations, and wherein said correction data includessaid capacity correction data corresponding to said capacityinformation.
 4. The system of claim 3, wherein said input informationfurther includes polarized voltage information of said storage device,and wherein said correction data includes said polarized voltagecorrection data corresponding to said polarized voltage information. 5.A system for detecting a state of an electric storage device comprising:a memory, wherein said memory stores storage information includingcharacteristic data of said storage device, calculation data requiredfor detecting said state, and set data based on a property of saidstorage device or a phenomenon caused therein; a calculator, whereinsaid calculator determines state information based on input informationincluding measurement data from a measurement instrument and saidstorage information, and wherein said calculator provides correctiondata corresponding to said input information when said state informationdiffers from said set data; and a correction unit, wherein saidcorrection unit changes said input information based on said correctiondata; wherein said input information includes internal resistanceinformation of said storage device, and wherein said correction dataincludes internal resistance correction data corresponding to saidinternal resistance information, and wherein said storage devicecomprises a lithium battery.
 6. A power supplying system comprising: anelectric storage device; a state detection system for determining astate of said electric storage device; and a measuring instrument fordetermining a parameter of said electric storage device and providingsaid parameter to said state detection system; wherein said statedetection system comprises a memory, wherein said memory stores storageinformation including characteristic data of said storage device,calculation data required for detecting said state, and set data basedon a property of said storage device or a phenomenon caused therein; acalculator, wherein said calculator determines state information basedon input information including measurement data from a measurementinstrument and said storage information, and wherein said calculatorprovides correction data corresponding to said input information whensaid state information differs from said set data, and wherein saidinput information includes internal resistance information of saidstorage device; and a correction unit, wherein said correction unitchanges said input information based on said correction data.
 7. Thesystem of claim 6, wherein said electric storage device comprises alithium battery.
 8. A power storage apparatus comprising: a controlconverter to which a commercial power source, a photovoltaic generationdevice, and a load device are connected through a plurality of switches;a controller, wherein said controller operates said plurality ofswitches and said control converter; an electric storage deviceconnected to said control converter; a state detecting system fordetermining a state of said electric storage device; a measuringinstrument for determining a parameter of said electric storage deviceand providing said parameter to said state detection system; whereinsaid control converter determines power flow between said electricstorage device and each of said commercial power source, saidphotovoltaic generation device, and said load device, wherein said statedetecting system and said controller are in communication with oneanother, wherein said controller operates based on information from saidstate detecting system, and wherein said state detection systemcomprises a memory, wherein said memory stores storage informationincluding characteristic data of said storage device, calculation datarequired for detecting said state, and set data based on a property ofsaid storage device or a phenomenon caused therein; a calculator,wherein said calculator determines state information based on inputinformation including measurement data from a measurement instrument andsaid storage information, and wherein said calculator providescorrection data corresponding to said input information when said stateinformation differs from said set data, and wherein said inputinformation includes internal resistance information of said storagedevice; and a correction unit, wherein said correction unit changes saidinput information based on said correction data.
 9. An apparatus for anelectric vehicle comprising: a control converter connected to a motor; acontroller, wherein said controller operates said control converter; anelectric storage device connected to said control converter; a statedetecting system for determining a state of said electric storagedevice; and a measuring instrument for determining a parameter of saidelectric storage device and providing said parameter to said statedetection system; wherein said control converter determines power flowbetween said electric storage device and said motor, wherein said statedetecting system and said controller are in communication with oneanother, wherein said controller operates based on information from saidstate detecting system, and wherein said state detection systemcomprises a memory, wherein said memory stores storage informationincluding characteristic data of said storage device, calculation datarequired for detecting said state, and set data based on a property ofsaid storage device or a phenomenon caused therein; a calculator,wherein said calculator determines state information based on inputinformation including measurement data from a measurement instrument andsaid storage information, and wherein said calculator providescorrection data corresponding to said input information when said stateinformation differs from said set data, and wherein said inputinformation includes internal resistance information of said storagedevice; and a correction unit, wherein said correction unit changes saidinput information based on said correction data.
 10. The apparatus ofclaim 9, wherein said electric storage device comprises a lithiumbattery.
 11. An apparatus for a hybrid vehicle comprising: a motorincluding a driving source for a wheel in combination with an internalcombustion engine; a control converter connected to said motor; acontroller, wherein said controller operates said control converter; anelectric storage device connected to said control converter; a statedetecting system for determining a state of said electric storagedevice; and a measuring instrument for determining a parameter of saidelectric storage device and providing said parameter to said statedetection system; wherein said control converter determines power flowbetween said electric storage device and said motor, wherein said statedetecting system and said controller are in communication with oneanother, wherein said controller operates based on information from saidstate detecting system, and wherein said state detection systemcomprises a memory, wherein said memory stores storage informationincluding characteristic data of said storage device, calculation datarequired for detecting said state, and set data based on a property ofsaid storage device or a phenomenon caused therein; a calculator,wherein said calculator determines state information based on inputinformation including measurement data from a measurement instrument andsaid storage information, and wherein said calculator providescorrection data corresponding to said input information when said stateinformation differs from said set data, and wherein said inputinformation includes internal resistance information of said storagedevice; and a correction unit, wherein said correction unit changes saidinput information based on said correction data.
 12. The apparatus ofclaim 11, wherein said electric storage device comprises a lithiumbattery.
 13. An apparatus for a hybrid vehicle comprising: means fordriving a wheel; converter means connected to said driving means;control means for controlling said converter means; electric storagemeans connected to said converter means; state detection means fordetecting a state of said electric storage means; and measuring meansfor measuring a parameter of said electric storage means and forproviding said parameter to said state detection means; wherein saidconverter means determines power flow between said electric storagemeans and said driving means, wherein said state means and said controlmeans are in communication with one another, wherein said control meansoperates based on information from said state detection means, andwherein said state detection means comprises memory means for storingstorage information including characteristic data of said storagedevice, calculation data required for detecting said state, and set databased on a property of said storage device or a phenomenon causedtherein; calculation means for determining state information based oninput information including measurement data from a measurementinstrument and said storage information, and wherein said calculationmeans provides correction data corresponding to said input informationwhen said state information differs from said set data, and wherein saidinput information includes internal resistance information of saidstorage device; and a correction means for changing said inputinformation based on said correction data.
 14. A method for detecting astate of an electric storage device comprising: storing storageinformation in a memory, wherein said storage information includescharacteristic data of said storage device, calculation data requiredfor detecting said state, and set data based on a property of saidstorage device or a phenomenon caused therein; determining stateinformation with a calculator based on input information includingmeasurement data from a measurement instrument and said storageinformation; providing correction data with said calculatorcorresponding to said input information when said state informationdiffers from said set data; and changing said input information based onsaid correction data with a correction unit; wherein said correctiondata includes internal resistance correction data corresponding tointernal resistance information of said storage device.
 15. A statedetecting system for an electric storage device comprising: a memorymedium storing storage information which includes characteristic data ofan electric storage device, calculation information required forcalculation for detection of a state of the electric storage device, andset information on a true set value or true logic based on acharacteristic of the electric storage device or a phenomenon causedtherein; a calculator which performs the calculation for detection ofthe state of the electric storage device on the basis of measuredinformation obtained from a measuring instrument for measuring aparameter of the electric storage device required for detection of thestate thereof and input information including the storage information,judges whether or not a discrepancy exists in state detectioninformation obtained by the calculation in comparison with the statedetection information and the set information, and outputs correctioninformation corresponding to the input information when the discrepancyexists as a result of the judgment; and a corrector for correcting theinput information on the basis of the correction information; whereinthe correction information includes internal resistance information ofthe power storage device, the calculator outputs correction informationcorresponding to at least the internal resistance information when thediscrepancy is found, and the corrector corrects the internal resistanceinformation on the basis of the correction information correspondingthereto.
 16. A state detecting system for an electric storage deviceaccording to claim 15, wherein the calculator judges a discrepancy to becaused and outputs the correction information corresponding to theinternal resistance, when detection information of overcharging oroverdischarging is obtained in a state where a charging or dischargingcurrent in the power storage device is an allowable charging ordischarging current or less.